From: Jeff Dike <jdike@addtoit.com>
Date: Tue, 26 Sep 2006 06:33:03 +0000 (-0700)
Subject: [PATCH] uml: Improve SIGBUS diagnostics
X-Git-Tag: v2.6.19-rc1~1089
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=6edf428ed177e333863a8e5c37751a9ec176f241;p=linux-2.6-omap-h63xx.git

[PATCH] uml: Improve SIGBUS diagnostics

UML can get a SIGBUS anywhere if the tmpfs mount being used for its memory
runs out of space.  This patch adds a printk before the panic to provide a
clue as to what likely went wrong.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---

diff --git a/arch/um/kernel/trap.c b/arch/um/kernel/trap.c
index ac70fa5a2e2..e5eeaf2b6af 100644
--- a/arch/um/kernel/trap.c
+++ b/arch/um/kernel/trap.c
@@ -227,9 +227,16 @@ void bad_segv(struct faultinfo fi, unsigned long ip)
 
 void relay_signal(int sig, union uml_pt_regs *regs)
 {
-	if(arch_handle_signal(sig, regs)) return;
-	if(!UPT_IS_USER(regs))
+	if(arch_handle_signal(sig, regs))
+		return;
+
+	if(!UPT_IS_USER(regs)){
+		if(sig == SIGBUS)
+			printk("Bus error - the /dev/shm or /tmp mount likely "
+			       "just ran out of space\n");
 		panic("Kernel mode signal %d", sig);
+	}
+
         current->thread.arch.faultinfo = *UPT_FAULTINFO(regs);
 	force_sig(sig, current);
 }